Even as "Star Wars" fans around the globe lined up for midnight screenings of "Revenge of the Sith" on Thursday, tens of thousands more skipped the lines and huddled around their PCs to download a DVD-quality bootleg of the anticipated final chapter.

Late on Wednesday, word of the high-quality copy spread quickly among the file-trading community, and by Thursday morning "Sith" was available on dozens of sites.

"There were rumors that a French screener had been leaked from Cannes, but that turned out to be a fake," said Andy Baio, who writes the technology blog waxy.org. "Then, I started noticing these files [Wednesday] night and I figured it would be a low-grade camcorder copy, which is the most common thing for same-day leaks, but as it turns out it's considerably better."

The 28-year-old Santa Monica, California, Web programmer said the file appears to be what's called an "internal work print," as indicated by the time codes on each frame, meaning that it was most likely derived from an official source, not a bootlegger with a camcorder in a theater. Baio has posted a link to a 20-second teaser showing a council between Yoda and the Wookies, as well as a series of stills, but he is not linking to the actual file.

"I don't think copies of this quality leaked this early for the other films," Baio said, referring to the two previous "Star Wars" episodes. "But by this point it's ballistic." He said the 1.4 gigabyte file would take someone with a fast connection at least 3 to 4 hours to download, but, given the crush of traffic, download times could stretch to an entire day. One reader of Baio's site claimed bootleg DVDs are already being sold on the streets of Mexico City.

According to BBC News, English authorities have seized sleeves for pirated DVD copies of the film, complete with an introduction from director George Lucas, that were being prepped for sale.

Like the Recording Industry Association of America's ongoing efforts to thwart illegal song-swapping, the Motion Picture Association of America has been fighting a battle to keep movies from being posted and traded online. According to research posted by Baio on his site in February, that battle is far from over.

Of all the films nominated for Oscars in 2004, he said, screener copies for 25 out of 30 were leaked online, with the films "Hotel Rwanda" and "The Sea Inside" appearing on the Internet before their official U.S. release dates. In the case of "Million Dollar Baby," he said, a screener version was available online less than three weeks after the movie opened, while the window for "The Aviator" was even smaller at two weeks.

"Fans have been lined up for days to see 'Revenge of the Sith,' " MPAA President Dan Glickman said in a statement released Thursday. "To preserve the quality of movies for fans like these and so many others, we must stop these Internet thieves from illegally trading valuable copyrighted materials online. ... My message to illegal file-swappers everywhere is plain and simple: You are stealing, it is wrong, and you are not anonymous. In short, you can click, but you can't hide."

A spokesperson for Lucasfilm did not return calls for comment by press time.